The present invention relates to the independent probe-sensing and microprocessor programmed monitoring at remote areas of pharmaceutical and other manufacturing and processing plants and the like, of physical parameters such as temperature, humidity, and pressure, the local logging storage of such data, the facility for removal of the probes from the various monitoring areas, and the digital readout acquisitions of their logged data at a reader central computer location; being more particularly concerned with improvements that remove limitations in the miniaturized construction and battery-powered electronics of such probe monitors, and also in the efficiency and facility of the central readout acquisition of the logged data stored in the multiplicity of probes.
Such miniaturized logger/sensors have been and are currently in wide use in many industries world-wide, including particularly in the chemical and pharmaceutical processing industries and the like for temperature, humidity, pressure, rotation, and other physical parameter monitoring at various remote areas of equipment, processing containers, etc.
Among these are, for example, the xe2x80x9cTrack/Sensexe2x80x9d monitoring and recording systems of EllabA/S of Denmark, described in their bulletin entitled xe2x80x9cTracksensexe2x80x9d; the xe2x80x9cDatatracexe2x80x9d of Mesa Laboratories of Colorado, stated to be constructed as described in U.S. Pat. No. 4,718,776; the xe2x80x9cGemini Data Loggersxe2x80x9d of the Orion Group of the United Kingdom, Australia and the United States described at the xe2x80x9cHOBOxe2x80x9d and other data loggers of Onset Computers Corporation as described in their website, the xe2x80x9cTemptalexe2x80x9d and other portable temperature acquisition and readout system of Sensitech, Inc. as described at their website, the RL100 temperature monitors of Ryan Instruments described at their website, and much earlier, similar miniaturized remote temperature sensors and computer read-out system described by P. Christiansen in an article entitled xe2x80x9cTemperaturverlaufe-An UnZugaanglichen Stellen Gemessinxe2x80x9d appearing in the Sep. 19, 1986 issue of xe2x80x9cElektronickxe2x80x9d, Vol. 35, No. 19; in French patent 2,219,405A (Felten and Guilleaume Carlswerk); in British patent GB2028614A (AEP International Ltd.); in WO8501817A (Thermo Electric International) and in German patent DE 31396631 (Bauer Bernhard), among others.
Many of these devices have the common concepts of portable miniaturized temperature-monitoring electrically conductive sealed housings containing therein a sensor and a microprocessor for processing the sensed signal and storing the same in digital form to produce digital output signals in accordance with programmings that are transferred to an operationally independent readout console unit when the sensor is removed, and with internal battery power within the sealed container. There are several different techniques and constructions in these similar miniaturized temperature sensor housings and systems for extracting the digital output signal data from the device. The above-mentioned Ellab device, for example, uses an infra-red path through a transparent window provided in the device; and the Mesa device, as another example, uses two isolated parts of the conductive housing as a two-conductor electrical output path.
In accordance with discovery underlying the present invention, a simpler, less costly and improved type of output signal data extraction is achievable through a novel capacitive coupled technique and without resorting either to optical output communication, with its problems of window manufacture, pressure differentials, scratching, and fogging when in different environments, or to the requiring of two electrically isolated electrical housing contacts for the output, wherein the stainless steel or similar conductive housing shells do not readily lend themselves to making such contacts, and the buildup of mechanical tolerances for such construction can leave this approach unreliable, as well as expensive.
An object of the present invention, accordingly, is to provide a new and improved miniaturized sealed-housing sensor of the type and for the uses above described, having a novel output signal capacitive coupled communication path construction that admirably obviates the previously delineated drawbacks of prior art optical and two isolated housing shell contact constructions and the like.
A further object is to provide a novel method of conducting the readout of pluralities of such improved sensors, as well.
A further object is to prevent accidental charging of the internal battery by the communication circuits.
Other and further objects will be explained hereinafter and are more particularly delineated in the appended claims.
In summary, however, the invention embraces, a method of outputting digital data stored in a housing sensor device comprising conductive base and cap sections sealed together by an insulating gasket and that has monitored a parameter such as temperature at a remote location and stored corresponding digital data, that comprises, removing the device from such location and inserting the same into a conductive well of cross-dimension made slightly larger than the housing and of depth substantially equal to the length of the base section, to capacitively couple the housing base section to the inner wall of the well; establishing a radio-frequency ground connection about the housing cap section protruding above the well; and communicating the data stored in the housing for external readout by installing a data outputting radio-frequency communication path through the capacitive coupling and the outer wall of the well.
Preferred and best mode designs and techniques are later detailed.